Improvement in reducing and bleaching paper-stock



UNITED STATES PATENT OFFICE.

.nARRIsoN R. Manen, or FORT EDWARD, New YORK.

IMPROVEMENT IN REDUCING AND BLEACHING PAPER-STOCK.

Specification forming part of Letters Patent No. 106,711, dated August 23, 18TH.

To all lwhom 'it may concern Beit known that I, HARRISON B. MEECH, of Fort Edward, in the county of W'ashington and in the State of New York, have nvented certain new and useful Improvements in Apparatus and Process for Reducing Straw, Vood, and other Fibrous Substances to a Pulp for Paper and I do hereby declare the following to be a full, clear, and exact description thereof, reference being had to the accompan ying drawing and to the letters of reference marked thereon.

The nature of my invention consists in the construction and application of an engineboiler for the purpose of disintegrating and separating the fibers from cach other, when boiling` paper-stock for pulp, by a grinding and rubbing operation at the same time the heat and chemicals are acting upon the stock, with as small an amount of chemicals as possible, and that the chemicals may act upon all the fibers equally without destroying them 5 also, for the purpose of bleaching said fibers white by agitation and ythe use of chlorine liquor, steam, air, and gas, it being very essential that the stock should be thoroughlyr agitated while bleaching.

In order to enable others skilled in the art to which my invention appertains to make and use the same, I will now proceed to describe its constructionand operation, referring to the annexed drawing, which forms a part of this specication, and in which- Figure l is an end view, showing the inside of boiler. Fig. 2 is a longitudinal vertical section; and Fig. 3 is a plan view7 a part of the boiler being broken away to show the wheel within the same.

A represents a steam-tight cylinder-boiler. m is the man-hole; s, the engine-shaft that turns the roller or wheel on the inside of the boiler; is the wheel or roller within the cylinderA. cistheliquorandwaterpipe,through which the liquor or water is forced through the perforated pipe c, as shown in Fig. 2. fr is the steam, air, and gas pipe, through which the steam is forced in at the mouth of the engine, and strikes all the stock, passes through under the engine wheel or roller w, and back around the sides between the space n, and so on around and through the engine-wheel until thoroughly ground. fr is the perforated false bottom, through which the liquor and wash water are drained off through the pipe d. q

is the discharge stock-pipe. p is a perforated pipe between the perforated bottom and the boiler, to admit water and steam. t is a testcock, for the purpose of testing a sample from time to time, to know when the stock is well reduced or bleached. o represents the backfall and bed-plate.

For reducing paper-stock the straw or wood is cut into short lengths and packed in the boiler; then a solution of sulphur and limewater is forced through pipes c cinto the stock; then boiled for about three hours by admitting steam through pipe yr, (at the same time the engine-wheel is run at about two hundred revolutions per ininuteg) then said liquor is drained oft' through pipe d. The stock may then be boiled again for about three hours by a pressure of steam of about fifty pounds to the square inch, in a weak solution of pure caustic soda of about one degree strength, Baiun, at the proportion of three quarts to one pound of straw.

For boiling wood use about three degrees strength to six hours time. This liquor is then drawn off and the stock washed by forcing water through pipe c, and, at the same time, letting the water drain oft' through pipe d. After washing the stock it is ready for bleaching.

For bleaching, the boiler should be about half-full of brown stock; then is added a solution of chlorine liquor of about one-half degree strength, Baume, in sufficient quantity so that the stock will be moved readily by the engine-wheel and agitated for about fifteen minutes; then steam, air, and chlorine gas are admitted through pipe r, andthe engine-wheel is revolved until the stock is thoroughly bleached, which can be ascertained by the test-cock t. Then the stock is ready to be made into paper.

A boiler with an engine-wheel on the inside, as described, may be used in combinationwith any known chemical process now in use. It is of a great advantage for grinding and boiling straw, &c.

Having thus fully described my invention, what I claim as new, and desire to' secure by Letters Patent, is-

1. The engine wheel or roller a; within a boiler as ai means of grinding and rubbing at 4. The pipe-r for the admission of zt jet of Jthe same time as boiling the fibers, for tbe steam at the mouth of the beatingengine at purpose of reducing paper-stock, as described. time of grinding, for the purpose of lbleaehiu g 2. The Within-described boiler A, provided the ber, as set forth.

With air and Water pipes, und used in eombi- In testimony that I claim the foregoing I nation with the Wheel or roller w, substantially have hereunto set my hand this 26th day or as und for the purposes herein set forth. July, 1870.

3. The process herein described oi' bleaching paperstoek, the suine consisting of the zippliea-tion within the boiler A of chlorine liquor, Iitiiesses: ehlorine gus, steam, and uir to the pulp, sub- F. LEHMANN, stantially as set forth. CHARLES H. FOWLER.

HARRISON Il. NEECI'I. 

